Infectious diseases are illnesses caused by pathogens such as bacteria, viruses, fungi, or parasites. These diseases can spread from person to person, through contaminated food or water, or via vectors like mosquitoes. Common examples include the flu, HIV/AIDS, and tuberculosis. Preventing infectious diseases often involves vaccination, proper hygiene, and public health measures. Understanding how these diseases spread and their impact on communities is crucial for effective management and treatment. Global efforts continue to combat outbreaks and improve health systems to reduce the burden of these diseases.